Kinetic process of the biosorption of Cu(II), Ni(II) and Cr(VI) by waste cells.

Waste biomass of cells from the fermentation industry is an environmentally friendly biosorption material. The present study aimed to explore the biosorption behaviour of waste cells for Cu(II), Ni(II) and Cr(VI) in aqueous solution conditions. The results showed that the adsorption kinetics of three kinds of metals were well-fitted with lineared Elovich, pseudo-second-order kinetics models, non-linear kinetics and adsorption isotherms. The effective biosorption rates for Cu(II), Ni(II) and Cr(VI) removal were 71.3%, 59.7% and 16.25% respectively. The maximum Cu(II) adsorption capacity of waste was 40 mg/g at pH = 4 and 225 mg/L of solute concentration for 0.4 g biomass, better than that of the living yeasts. The pattern of Fourier transform infrared (FTIR) indicated that functional groups such as -NH, -OH, Si-O, P-O-C were involved in Cu(II) adsorption process. The analysis of SEM-EDS, XRD and TEM-EDS can be concluded that Cu(II) occupied Ca(II) binding sites by ion exchange mechanism to remove flocculation, and Cu(II) adsorbed onto the diatomite containing in the industrial waste . Thus the adsorption mechanism of the industrial waste was proposed taking Cu(II) as the example. And consecutive biosorption/desorption cycles were used for the evaluation of the regeneration efficiency, suggesting the good regeneration and reusability of waste .